Automatic drain valve for compressed air reservoirs



11% 1950 L. L. HAM IL ON 2,509

AUTOMATIC DRAIN V VE FOR COMPRESSED AIR RESERVOIRS Filed. Aug. 19, 1946 ATTORN EY Patented May 30, 1950 Y-UN'I'TED sures PATENT @QFFWE "AUTOMATIC DRAIN VALVE '?F(DR"-C@M- RRESSED AIR RESERVOIR'S Lloyd L. Hamilton, OklahomaCity, Okla.

Application August :19, 1946,-Se1'ialNo.--691;627

1 My invention relates to air-brake and analogoussys'tems, andparticularly to mechanism for eliminating =orbleeding oil condensation of .moisture from such systems.

'In most air-pressure actuated brake systems and'others'in which airfis compressed and stored, moisture condenses within the system from the compressed air utilized therein. Such moisture not only causes corrosion of metal parts, but often collects to such an extent in thecompressed air reservoir that "freezing renders the system inoperative.

The principal object of the present invention is to provide anim'proved automatic drain valve which eliminates such condensation from the "system.

Another object is to provide a moisture eject- 'ing valve mechanism which is simple to install, comparatively cheap to manufacture, and which has few moving parts tobecome worn or to get out of order.

Other objects willbe'apparen'tfrom the following description when taken in conjunction with the accompanying single sheet of drawings, wherein:

The figure is a schematic View of a portion of a simple vehicle air operated brake system, the bleeder valve mechanism-of the present invention being shown in vertical section, and at an enlarged scale.

Like characters of reference designate like parts in those figures of the drawings in which they occur.

In the drawings:

The reference numeral 1 indicates, as a whole,

an air compressor unit having its exhaust line 2 connected to an air storage tank 3. The tank 3 has an air outlet'line 4 leading-through a control valve 5 to an air delivery line 6 which in turn leads to brake operating (mechanism, not shown. A foot lever .1 controls -operation of the valve 25 and consequently communication between the air lines! and 6.

The above described mechanism is usual to conventionaleir brake systems, and is not apart of -'the;.prescn.t invention, except that it is in :con nection with such a system that the present invention is designed to function.

In such air brake systems, moisture from the compressed air in the tank 3 is prone to condense into liquid, and unless bled from the tank, such moisture eventually retards efiicient operation of the system. It is the bleeding of such moisture from the tank 3 which the present invention is designed to accomplish.

Thapresent invention, -perise,.includes1a bonnet it having a central :attaching nipple with a through bore |-l,=1and having upper threads M whereby it \may he installed within an opening .13 in the bottom 'of thetank Flhevlower peritiOIl-Of the bonnet hasvan exterior annular :fiange -lfl, and therebelow is exteriorly threaded to re -ceive the upper-open"end of :avalve housing l5.

The valve housing hajs "a solid horizontally disposed bodyportiondt which forms the bottom of a cavity complementally [formed by the housing-and the-bonnet. The=cavity=la1=liesat the lower end of the "bore II and is :adaptezlto "receive rtherethrough zany condensation of moisture which may occur? inlthe tank 3. ilm'e body porti'cn t5 has a vertical through bore T8, and there'- below, the :housing 15 is completed iby the provision of a, substantially bell-shaped or annular wall is having an outwardly protecting annular flange '20 around its lower open end. The body portion I 6 :of the housing has a horizontal bore '2'! which intersects the vertlca l bore f8 and the walls l9 have a plurality oi outletperforations 3!].

Attached to "the flange ot the housing by bolts -22, "is a metal cup "2'3 having a threaded opening 2 in one wall. flexible "diaphragm has its continuous edge portion impinged between the cup 23 and the flange 20, and is held rigidly in place by the tightened bolts 2 2. The bell-shaped wall 19 and the cup 23 complementally 'form a chamber within which the central portion of the diaphragm "may work vertically, and which is hermetically divided horizontally by the diaphragm into upper and lower compartments. The two compartments are respectively indicated by the reference numerals '26 and 21.

slidably disposed vertically W thin the two vertical bores H nd i8, but of considerably-less diameter hanhe bore I is provided a reciprocatable valve stem '28, The upper .end or section of the valve stem. is .preterably tapered,,and the lower end thereof extends downwardly into the compartment 26 and is threadedly anchored within a socket member '29 which may be at.- tached by any suitable means to the upper sur face of the imperforate diaphragm 25. A suitable helical compression spring 3| is provided within the chamber 26 and around the valve stem 28, and acts to normally maintain the diaphragm and stem at the lower end of their permitted travel. A suitable hydraulic packing is provided in the upper end of the bore l8 and around the stem 28.

Within the cavity I1, the valve stem 28 is provided with a rigidly mounted ball valve 32 which is adapted to normally seat in the upper end of the bore I8 and close the same. The spring 3| acts to hold the ball 32 in said seated position under normal conditions, and. air pressure from the tank 3 therefore is normally present in the cavity 17. A removable valve seat member 33 may be provided in the upper end of the bore l8, if desired.

Should the diaphragm 25 be forced upwardly, and consequently raise the valve stem 28, the ball 32 will likewise be moved upwardly to close the lower end of the bore H. Such movement will, of course, open the bore I8 and will thereby open communication between the cavity l1 and the atmosphere around the device through the bores I 8 and 2|. A removable valve seat 34 may, if desired, be provided in the lower end of the bore II.

It is thought to be obvious that under normal conditions, and during the time the ball valve 32 is in its lower seated position, any moisture which might normally accumulate in the tank 3 will gravitate to and be retained within the cavity l1, and as stated hereinabove, such moisture will be under such pressure as is present in the tank 3 due to action of the compressor I. Should the ball valve be forced to its upper seated position, any fluid, either liquid or air, then residing in the cavity I! will expand and exhaust from the cavity through the bores l8 and 2| to the open air. Therefore, should the valve 32 be moved upwardly with suflicient frequency, moisture condensation in the tank 3 would'be entirely eliminated, or would at least be retarded to the extent that the cavity I1 would fully accommodate such condensation.

As a means for intermittently reciprocating the ball valve 32, the air line 6 is provided with a branch-line 35 leading to the opening 24 in the cup 23. Every time the brake pedal 1 is moved to open the valve 5, compressed air will travel from the line 6 through the branch-line 35 to the chamber 21 beneath thediaphragm 25. Due to the fact that the exposed area of the diaphragm is greater than the upper area of the ball valve 32, the diaphragm will be flexed upwardly, and will consequently move the valve stem and ball upwardly. The result is that accumulated moisture is bled from the cavity ll every time the brake system is operated. This is normally often enough to take care of moisture condensation under ordinary weather conditions, but any amount of condensation may be exhausted by merely actuating the foot pedal 1 a few times in rapid succession.

It is also pointed out that the bleeding mechanism could well be located at any point in the air brake system where moisture condensation is likely to occur, and that if desired separate valve actuating controls, other than the pedal 1, could well be provided. The improved drain valve has been found tov be highly effective in removing condensed water, oil and sludge that accumulate in the air tanks or reservoirs on motor trucks,

and buses and other automotive vehicles having air brakes, but it may be used on the air storage tanks of service station compressors and in other ways.

Obviously the invention is susceptible to some change or alteration without defeating its practicability, and I therefore do not wish to be confined to the preferred embodiment shown in the drawings and described herein, further than I am limited by the scope of the appended claim.

I claim:

A valve of the character set forth comprising a casing body formed with a horizontal portion having a central vertical bore, a cylindrical wall concentric with bore and extending upwardly from said body portion to form a drain compartment, and an annular wall concentric with said bore and extending downwardly from said body portion, a bottom casing section removably secured to the lower edge of said annular Wall and having a pressure-fluid inlet, a flexible imperiorate diaphragm having its edge clamped between said annular wall and said bottom section to seal said inlet from said bore, a top casing section removably secured to the upper edge of said cylindrical wall to close said drain compartment, said top section having a central vertical bore axially alined with the bore in said body portion and a drain-inlet attaching nipple through which said bore extends, the bottom of said top section and the top of said body portion being provided with opposed valve seats concentric with said bores, a valve in said drain compartment to alternately engage said seats, an upper stem projecting from the top of said valve and slidable in the bore of said top section, a lower stem projecting from the bottom of said valve and slidable in the bore of said body portion, said lower stem having an externally screw threaded lower extremity terminating above said diaphragm, a removable socket member engaged with the threaded extremity of said lower stem, and a coil spring surrounding said lower stem between said socket member and said body portion to normally hold said valve closed on the seat on said body portion, said casing having means permitting the escape of the contents of said drain compartment through the bore in said body portion when said valve is lifted from the last-mentioned seat.

LLOYD L. HAMILTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,520,124 Gottschalk Dec. 23, 1924 1,680,288 Gottschalk Aug. 14, 1928 2,316,052 Dach Apr. 6, 1943 2,326,687 Sanford Aug. 10, 1943 2,328,649 Jerome Sept. 7, 1943 2,330,040 Fitch Sept. 21, 1943 2,347,939 Down May 2, 1944 

